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(Breeding koi fish) you need to know about right this year 2017 for the first time

Giovanni Carlo 0

Breeding koi fish tips

Breeding koi fish First important Step is How to quickly will make you identify male and female koi fish You need to know watch the video below

Also check the male breeders if they are ready to be breed by checking if they have enough milt and sperm watch video below on how to do it.

koi breeding setup 

My koi breeding setup is simple DIY breeding koi pond tank and the materials I used are bamboo for the koi pond frame and Trapal for the liner.

bamboo trapal koi pond


how old do koi have to be to breed

Koi fish are sexually matured when they are about 1-year old already but it is not advisable to breed them at young age because the membrane of the female egg is thin yet and the outcome is high mortality rate of the koi fry, It is hard to determine koi fish age if you just bought it from somebody else or at the pet store, since sizes will not determine koi fish age, because koi fish that are placed in smaller koi pond grows slow, so tendency some will breed even if their sizes are small because of their age are sexually matured already.

Separate the female koi fish breeder

First I did is I take out the female koi fish breeder and separate it from the koi fish males breeder this will help the female koi fish breeder develop enough eggs. The reason for this is if the female koi fish is mix with males at community pond the males will mate her from time to time and you will not notice this because they will usually mate at dawn or early morning. Photo below shows a female koi fish breeder prior from separating as you notice it’s tummy is not swollen yet this means that it has not enough eggs yet.

female koi fish showa breeder Breeding koi fish
Here is a photo of a koi fish female breeder prior from separating and conditioning

Watch the video here 

I feed the female koi fish lots and lots of high protein prepared koi food and live foods. Here is the list of live foods I feed the female koi fish so with the male breeders also.

Live foods for koi fish 

  • Daphnia
  • Earth worms
  • Snails
  • Tubifex
  • Shrimp

I also gave them duckweed, green pea, and wheat germ. after one month from separation. I check the female koi fish breeder if the tummy is swollen already I gently touch it’s tummy if it soft already. If the tummy is soft to touch this indicates that it is ready to breed. Pro tip it is best also to breed them during a full moon. The full moon will help stimulate the breeders to breed. Here is the photo of the female koi fish breeder after a month of separation

female koi fish breeder after separation Breeding koi fish
Here is the photo of the female koi fish breeder after separation tummy swollen already


And you can also watch the video here

I gently touch the female belly if it is soft this indicates that it is ready to spawn.


Preparing the koi pond for breeding 

  • I change the water 60 % and leave the water dripping slowly this will stimulate them to breed too.
  • Add nesting media I created a floating yarn and net

Adding the koi fish breeders 

I add the koi fish together at 6 pm in the evening and note this was also done at the full moon. I check them at 12:00 midnight if they already breed but there was no breeding sign yet, breeding sign is female will gather the nesting media and seems like creating bubbles and males will chase her, so I just leave them and then when I wake up at around 5:00 am in the morning they are already chasing and breeding here is the actual video of them breeding watch koi fish actual video breeding 

Remove the koi fish breeders after they are done mating. You will notice if they are already done mating when the males no longer chase the female koi fish breeder.  You need to remove them fast immediately because after laying eggs they will start eating their eggs. Then perform 60% water change this will prevent from water to be foul because of the sperms. Place methylene blue to prevent the molds attacking the eggs.

how fast do koi fry grow this will depend on the temperature the water the climate the faster they grow because warmer temperature stimulate their metabolism and this will trigger them to eat fast.
Here is a video of a koi fry growth chart watch it here
koi fry growth rate in the first week from hatching their sizes are about 1 cm and their koi fry color are all yellow yet. you can watch this video of my 1-week old koi fry

how fast do baby koi grow to depend on the temperature, size of the pond and sources of live foods. If you feed them daily with live foods they grow too fast also if your temperature is warmer they tend to feed more in warmer temperature because warm climate makes their metabolism fast, so they get hungry all the time.
koi eggs hatching depends on the temperature here in my place which is tropical and warm koi eggs hatch in 2 days in colder region koi eggs hatch for 7 to 10 days.
3-week old koi fry
what do baby koi fish look like It really depends on the stage for the first-week yellow, second week two colors appear black and yellow, third week 3 colors? If you want to see baby koi fish fry see my video below

1-Week Old Koi Fry Video

2-Week Old Koi Fry

3-Week Old Koi Fry

4-Week Old Koi Fry Video

5-week old koi fry video

5 week old koi fry


6-week old koi fry video

Here is the vidoe of my 7-week old koi fry now

Update of our koi fry today, they are now 8-week old koi fry, here’s a video below

Update today the koi fry are now 9-week old koi fry their number decreases because I was not able to remove the tobi koi fry and last week also the water quality was degraded because some of the clams died and also their pooh increase already since they are growing to watch the video below


Here is an article about Tobi koi fry from

Steve Hopkins
Rain Garden Ornamentals
June 2007
Anyone who breeds koi knows about tobi. In other species these are often called
“shooters”. They occur in goldfish spawns too. They are the fry that grow to juvenile
size very quickly. They are noted for eating their smaller siblings. Most tobi koi do not
have the refined characteristics the breeder is looking for, although some do.
I have never seen a good explanation of how and why tobi develop. If anyone knows of
an authorative description, please let us know. Until then, I will give you my off-the-wall
theory about tobi. I think tobi are hard to explain because there are two factors at work,
genetics and blind luck.
Koi and goldfish carry in their genetic code remnants of everything that come before. A
top-notch pair of gosanke or ranchu carries all the genetic material needed to make the
ancestral common carp or crucian carp from which they were derived through selective
breeding. They also have all the genetic material needed to recreate the incremental
steps in their evolution. In the offspring from a pair of sanke you will find kohaku, higoi
and perhaps even a magoi. A group of ryukin offspring may include individuals with
characteristics of wakin and common goldfish.
The more ancestral forms are always more hardy. Left to their own devices and
allowed to breed indiscriminately for many generations, a population of koi will revert
back to something resembling the ancestral common carp and goldfish will revert back
to something resembling a crucian carp. In a group of sibling fry, those with a more
primitative genetic make-up will be just a little bit stronger and faster giving them a slight
advantage when it comes time to eat or avoid a predator.
But, in the world of fish fry, a slight advantage can become amplified many fold. There
is a snowball effect. A fry that gets just a little bit bigger than its siblings is better able to
capture and compete for food so it grows faster. The larger the size disparity, the
bigger the advantage. So, over just a few weeks time an individual that is just slightly
larger than its siblings becomes ten times larger than its siblings. At some point, the
size disparity becomes so great that the larger individual can eat its siblings providing it
with a new limitless food supply. The snow ball effect escalates.
Blind Luck
But, how can some tobi be excellent examples of highly refined koi or goldfish and show
no signs of being a throw-back to an ancestral form? I think it is because there is a
blind luck factor at work as well.
Imagine a group of larvae which have absorbed their yolk sack and are ready to begin
feeding. Perhaps some arrive at this stage a few hours ahead of the rest because they
were spawned first or their position on the spawning substrate was a fraction of a
degree warmer then the rest, or because of some other factor. The larvae instinctively
dart at a moving food particle. Some times they catch it and sometimes they miss.
They are growing extremely rapidly and catching one or two extra choice food morsels
can make a difference in that growth rate. Some individuals are just lucky and are able
to get a tiny bit ahead of their siblings. As described above, a very small advantage can
quickly snowball into a large advantage. An individual with no innate genetic advantage
can become a tobi just through bind luck.
Another Observation
In some batches of fry the size distribution is large and there is an unusually large
number of tobi. In other batches the size distribution is narrow and the siblings look
almost identical. In general, the better the fry are fed the less variation there will be in
their size. If abundant live food can be kept in front of the fry at all times while
maintaining good water quality, there is a much lower incidence of tobi. Under the best
of conditions the growth of fry is phenomenal and most of the population (except for
those with serious deformities) has the potential to grow at the rate of tobi. The best
way to minimize the number of tobi is to provide better nutrition and husbandry.
The biggest and best koi and goldfish will have had the best nutrition and water quality
their entire lives. Periods of less than optimal conditions can have long-term effects. In
extreme cases, we say that the fish is stunted. The younger the fish, the more severe
and lasting the effect of poor nutrition and water quality.
Tobi are considered by most to be undesirables. If they are genetic throw-backs then
they probably are undesirable. However, you should be on the look-out for those fish
which have both the genetic potential to meet your selection criteria and the good luck
to have gotten off to a fast start in life and become a tobi. It is always a good idea to
separate tobi if you can; especially if they have become large enough to be cannibals.
But, do not automatically assume they have no potential.

Update of my koi fry check out this video

To be continue…

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